PHYL141 LAB review

What connects muscle to bone?

What connects muscle to bone?

tendons

What find of filament is Actin considered as?

Thin filament

What surrounds a fascicle?

perimysium

What are the three types of muscle tissue

skeletal, cardiac, and smooth

What surrounds a muscle

epimysium

What are a group of muscle fibers called?

fascicle

What is the smallest functional unit of a muscle?

Sarcomere

What type of muscle tissue(s) is/are striated?

Cardiac and skeletal

What muscle tissue is voluntary?

Skeletal

What neurotransmitter initiates a muscle contraction?

Acetylcholine

Describe Actin

It is a thin filament, has troponin and tropomyosin attached to it, and has active sites located on it.

Describe Myosin

Has a head that can pivot

What causes a muscle to shorten?

Myosin binding to actin which then pulls fibers towards middle

WHat happens when calcium reaches the sarcomere?

Binds to troponin, pushing tropomyosin out of the way

Which occurs FIRST in muscle contraction?

Acetylcholine is transferred from nerve to muscle cell?

What is A pointing to?

Tendon

What is B pointing to?

Epimysium

What letter is D pointing to?

Fascicle

What letter is G pointing to?

Muscle Fiber

WHat is this a picture of?

Sarcomere

What is the red molecule in the following picture?

Myosin

What is the blue molecule in the following picture?

Actin

For muscles to work, they need to..

Contract (shorten)

How do they contract?

Through the ACTION POTENTIAL of the motor neuron

What does the Action potential of the motor neuron do?

Release neurotransmitters form presynaptic vesicles of peripheral nerves

what are the 3 events that happen when skeletal and cardiac muscle fibers contract?

1) Electrical excitation of muscle fiber (action potential)

2) Excitation contraction coupling (complicated portion)

3) Shortening of muscle fibers (contraction)

Resting Membrane potential

When cells are at “rest'“, the electrical charge is anywhere from -60 to -90 mV (typical range)

During Resting Membrane potential

There are moer K+ inside of the cell and more Na+ OUTSIDE of cell as plasma membrane is more permeable to K+ ions

SO resting membrane potential is MORE NEGATIVE inside of the cell

WHat are the 3 basic types of muscle fibers

Slow Fibers, Fast Fibers, Intermediate fibers

Slow fibers

slow response/contraction, longer sustained duration

Fast fibers

quick contraction, short duration

Intermediate fibers

In between

Strength of contraction is dependent on what?

The number of muscle fibers recruited

Isotonic muscle contraction

same tension, chnaging length

ex. walking, running, or walking

Isometric muscle contraction

same length, changing tension

ex. plank or wall sitting (you stay still wihtout lenghtening or shortening leg muscles)

Muscles of the Upper limb are comprised of 3 main sections

1) Muscles that move the brachium

2) Muscles that move the antebrachium

3) Muscles that move the manus

What are muscles that aid the musle and is known as the “primary mover” of a muscle

synergist muscle

Name some synergist muscles that aid in arm movement

subscapularis, supraspinatus, infraspinatus, deltoid, teres major/minor, and latissimus dorsi

The synergist muscles of the Pectoral Girdle aid..

stabilization of pectoral girdle

allows for wider range of motion

corresponds to wide range of bone marking gound in this region

relates to the size and density of the bones in the pectoral girdle region

T-Tubules (Transverse tubules)

sarcolemma indentation at the junctons betweem A and I bands

Terminal cisterns

Cross channels

Sarcoplasmic reticulum SR

Smooth endoplasmic reticulum in muscle cells, regulates CALCIUM COCENTRATION

The small fluid-filled gapin between the neuron and muscle fibers is called the..

synaptic cleft

Botox is the diluted form of what type of toxin?

Botulinum Toxin

Name the types of mucles

Agonists (prime movers), Antagonists (opposite of antagonists), Synergists, and Fixators

Agonist

Prime mover. muscles responsible for a particular movement

Antagonist

opposite of agonst, muscles that OPPOSE OR REVERSE that movement

Synergists

aid the action of agonist by assistance or reducing unnecessary movement

Name muscle fascicle patterns and examples of where you would find them

circular (orbicularis oris), convergent (pectoralis major), unipennate (Extensor digitorum longus), bipennate (rectus femoris), multipennate (deltoid), parallel (sartorius), fusiform biceps brachii)